St. John’s wort, also known as hypericum perforatum, is a flowering plant of the genus Hypericum and has been used as a medicinal herb for its antidepressant and anti-inflammatory properties for over 2,000 years. The Greek physicians of the first century recommended the use of St. John’s wort for its medicinal value, and the ancients believed that the plant had mystical and protective qualities.
If you have little experience with this powerful herb, you may be questioning “what does St. John’s wort do for the body?” St. John’s wort uses, dating back to the ancient Greeks, include treatment for illnesses such as various nervous or mood disorders.
It may be a funny-sounding name, but the benefits of this herb are no joke. And the name was given to the plant because it blooms around June 24, the birthday of John the Baptist, and the word “wort” is an old English word for plant.
St. John’s wort is most commonly used as a natural remedy for depression and other common issues such as anxiety, tiredness, loss of appetite and trouble sleeping. It’s also used to treat heart palpitations, moodiness, the symptoms of ADHD, obsessive-compulsive disorder, seasonal affective disorder and menopause.
What Is St. John’s Wort?
The genus Hypericum consists of approximately 400 species of herbs and shrubs that have yellow or copper-colored flowers with four to five petals, numerous stamens and a single pistil. The plant flowers are used to make extracts, capsules and teas that possess therapeutic properties.
The St. John’s wort plant is native to Europe, but is commonly found in the United States and Canada in the dry ground of roadsides, meadows and woods. Although not native to Australia and long considered a weed, St. John’s wort is now grown there as a crop, and today Australia produces 20 percent of the world’s supply.
Pharmaceutical companies, particularly in Europe, prepare standard formulations of this herb that are taken by millions of people.
St. John’s wort produces dozens of biologically active substances, but two compounds found in the plant, hypericin and hyperforin, have the greatest medical activity. Other compounds, including the flavonoids rutin, quercetin and kaempferol, also appear to have medical activity. It’s also used in homeopathy.
1. Works as an Antidepressant
Many studies show that St. John’s wort may help fight mild to moderate depression and anxiety and has fewer side effects than most other prescription antidepressants, such as loss of sex drive. However, there are St. John’s wort drug interactions, so the herb should be taken only under the guidance of a healthcare professional, especially if you already take medications for depression.
In a 2017 meta-analysis including 27 clinical trials and over 3,800 patients, researchers concluded that St. John’s wort has comparable efficacy and safety to SSRIs.” Studies show that St. John’s wort uses seem to work as well as selective serotonin reuptake inhibitors (SSRIs), a popular type of antidepressant that doctors often prescribe first to treat depression, such as Prozac, Celexa and Zoloft.
Researchers aren’t exactly sure how St. John’s wort works for depression; some have suggested that the herb acts similar to a SSRI because it makes more serotonin, dopamine and norepinephrine available in the brain. These neurotransmitters help improve your mood and can be responsible for treating symptoms of depression.
In studies using the rat forced swimming test, an animal model of depression, St John’s wort extracts induced a significant reduction of immobility. In other experimental models of depression, including acute and chronic forms of escape deficit induced by stressors, St John’s wort extract was shown to protect rats from the consequences of unavoidable stress.
St. John’s wort uses also include improving mood in people with seasonal affective disorder (SAD), a type of depression that occurs during the winter months because of lack of sunlight. SAD is usually treated with light therapy, and there is some evidence that using St. John’s wort together with phototherapy works even better as a way to beat the winter blues.
2. Relieves PMS Symptoms
Because of its positive effects on mood, St. John’s wort has been used to alleviate and naturally remedy PMS symptoms, such as depression, chronic fatigue and hormonal imbalance.
A study done at the Institute of Psychological Sciences in the United Kingdom included 36 women aged 18–45. They had regular menstrual cycles and were diagnosed with mild PMS. The women were randomly assigned to receive either St. John’s wort tablets at 900 milligrams a day or identical placebo tablets for two menstrual cycles; then the groups switched doses and the next two cycles.
Symptoms were rated daily throughout the trial using the Daily Symptom Report, and the women reported on feelings of depression, aggression, hormone balance and hormonal stimulation. The trials showed that St. John’s wort is superior to a placebo in improving physical and behavioral symptoms of PMS, but there were no significant effects compared with a placebo in treating mood and pain-related PMS symptoms.
Researchers reported that daily treatment with St. John’s wort was more effective than placebo treatment for the most common physical and behavioral symptoms associated with PMS, and further work is needed to determine whether pain and mood symptoms benefit from longer treatment duration.
3. Improves Mood During Menopause
St. John’s wort uses include being tested as an herbal remedy that relieves the psychological and vegetative symptoms of menopause. A study published in Advance in Therapy and performed in Berlin investigated 12 weeks of treatment with St. John’s wort; 111 women, ages 43 to 65, took one 900 milligram tablet three times daily. All of the participants experienced symptoms characteristic of the pre- and postmenopausal state.
The treatment outcome was evaluated by the Menopause Rating Scale, a self-designed questionnaire for assessing sexuality, and the Clinical Global Impression scale. To test the results, the incidence and severity of typical psychological, psychosomatic and vasomotor symptoms were recorded after five, eight and 12 weeks of treatment.
Substantial improvement in psychological and psychosomatic symptoms was observed, and menopausal complaints diminished or disappeared completely in 76 percent of the women; in addition to this, sexual well-being also improved after treatment, displaying that St. John’s wort uses include providing natural menopause relief. It’s one of the most recommended menopause supplements.
4. Fights Inflammation and Skin Irritations
St. John’s wort has antibacterial properties and may also help fight chronic inflammation. When applied topically, it relieves symptoms associated with minor wounds and skin irritations, working as a natural treatment for eczema, a home remedy for burn relief and a way to naturally treat hemorrhoids.
St. John’s wort shows anti-inflammatory properties due to its inhibitory effects on pro-inflammatory genes like cyclooxygenase-2, interleukin-6 and inducible nitric-oxide synthase. These genes play a critical role in chronic inflammatory diseases.
St. John’s wort extracts have been used for thousands of years to treat cuts and abrasions. Its usefulness in reducing inflammation is well-known and appears to be related to its ability to serve as an antibacterial agent.
In a 2003 study at the Department of Dermatology at the Freiburg University Clinic in Germany, 18 patients with eczema were treated twice daily over a period of four weeks. After the trial, the severity of the skin lesions improved on sites of treatment, and skin tolerance and cosmetic acceptability was good or excellent with the St. John’s wort cream.
And in a 2017 case study, St. John’s wort extract provided significant efficacy for the treatment of pressure sore wounds in an intensive care unit patient.
5. Improves Symptoms of Obsessive Compulsive Disorder
Obsessive compulsive disorder (OCD) is a mental disorder where people perform certain routines repeatedly and are unable to control their thoughts or activities. This can be a debilitating condition, so the data that suggests the positive effects of St. John’s wort are indeed promising.
A study done at the Dean Foundation for Health Research and Education analyzed 12 patients who were diagnosed with OCD; the participants were treated for 12 weeks, with a fixed dose of 450 milligrams of 0.3 percent St. John’s wort twice daily. The study included weekly evaluations that were conducted with the Yale-Brown Obsessive Compulsive Scale, the Patient Global Impressions of Improvement Scale and the Clinical Global Impressions of Improvement scale, and a monthly evaluation with the Hamilton Rating Scale for Depression.
Significant changes occurred within one week and continued to increase throughout the trial. At the endpoint, five of the 12 patients were rated “much” or “very much improved” on the clinician-rated CGI, six were “minimally improved,” and one had “no change.” The most common side effects reported were diarrhea and restless sleep. Because improvement began at one week, and grew over time, researchers believe that St. John’s wort can be a helpful tool in treating OCD, and more placebo-controlled studies should take place in the future.
6. Has Anti-Cancer Properties
Researchers have found that St. John’s wort stops the growth of tumor cells and can treat both nonmelanoma and melanoma skin cancer cells. Because St. John’s wort has shown to have significant antitumor activity, researchers suggest that it’s an effective cancer-fighting treatment that’s available in abundance because it’s a naturally occurring plant.
Data from a 2003 study done in Spain indicates that hyperforin, a derivative found in St. John’s wort, is a compound that interferes with key events in angiogenesis — the formation and growth of cells. This confirms the recent and growing evidence about a potential role of this compound in cancer and metastasis inhibition and makes it a promising drug for further evaluation in the treatment of angiogenesis-related pathologies.
7. May Support Smoking Cessation
A systematic review conducted in Canada found that St. John’s wort may promote smoking cessation by alleviating tobacco withdrawal symptoms and decreasing negative effects through various mechanisms.
Researchers suggest that the herb is able to inhibit monoamine oxidase A and B, and is involved in dopamine and noradrenaline reuptake. These actions help to reduce symptoms associated with smoking cessation.
St. John’s wort can be obtained from your local health food store in many forms, including capsules, tablets, tinctures, teas and oil-based skin lotions. You can also find St. John’s wort in chopped or powdered forms.
Most products are standardized to contain 0.3 percentage hypericin, but make sure to read the label before making your purchase. Herbal supplements aren’t regulated, so you need to make sure you take the right product for your needs.
How long does it take for St. John’s wort to work? Know that you will not feel an immediate response. It generally takes a few weeks to several months to feel the benefits of St. John’s wort, so be patient and do not increase your dose without consulting your doctor first.
Most studies on St. John’s wort have been conducted in adults, but one study involving more than 100 children under the age of 12 indicated that St. John’s wort may be a safe and effective way of treating mild to moderate symptoms of depression in children.
If you are thinking about giving your child St. John’s wort to treat depression, you should absolutely consult with a medical supervisor first. Children being treated with St. John’s wort must be carefully monitored for allergic reactions and side effects, such as diarrhea and upset stomach.
For adult use, the typical dose in capsule form is 300 milligrams, three times daily with meals. You should consult your healthcare professional before taking more than the standard dose of St. John’s wort. To improve a specific condition, you may benefit from the following recommended doses (under the guidance of your healthcare professional):
- For anxiety, take 300 milligrams of St. John’s wort by mouth three times daily.
- For mild to moderate depression, take 300 milligrams three times per day, with meals.
- For severe depression, take about 900 milligrams of St. John’s wort by mouth daily for eight to 12 weeks (with doctor approval).
- For psoriasis, use St. John’s wort ointment two times daily on the skin for four weeks.
- For wound healing, use 20 percent St. John’s wort in petroleum jelly on affected skin three times daily for 16 days.
- For menopausal symptoms, take 300 milligrams once daily for 12 weeks.
- For PMS, take 300–900 milligrams of St. John’s wort by mouth daily for two menstrual cycles.
- For irritable bowel syndrome, take 450 milligrams twice daily for 12 weeks.
- For nerve pain, take three 300–900 microgram hypericin tablets by mouth for two treatment periods of five weeks each.
- For obsessive-compulsive disorder, take 450–900 milligrams by mouth daily for 12 weeks.
If you are taking a dosage above 300 milligrams, three times daily, consult your healthcare professional first. Also, it is best to reduce your dose slowly over time, instead of stopping St. John’s wort suddenly.
Risks, Side Effects and Interactions
Extensive research supports that St. John’s wort uses are safe when taken by mouth for up to three months, and some evidence suggests it can be used safely for over one year. St. John’s wort side effects include trouble sleeping, vivid dreams, restlessness, anxiety, irritability, stomach upset, fatigue, dry mouth, dizziness, headaches, skin rash, diarrhea and tingling.
Keep in mind that it generally takes weeks or even months for St. John’s wort benefits to become noticeable. It is not a fast-acting treatment for conditions like depression and increasing your dose isn’t going to make it work immediately. You need to give it time. When taken in large doses, St. John’s wort may cause severe reactions to sun exposure, so be sure to wear sunblock outside, especially if you are light-skinned.
Taking St. John’s wort is not recommended for women who are pregnant or breastfeeding; it’s most likely safe for children between the ages of 6 and 17, but they shouldn’t take it for more than eight weeks.
There are a number of health cautions pertaining to St. John’s wort uses that need to be considered before use. Recent research shows these interactions result from the ability of St. John’s wort components to produce intestinal or hepatic enzymes that either remove drugs from the body or metabolize them to inactive forms.
Some cases have found that it can interfere with conceiving a child, worsen the symptoms of ADHD when taking medication already, lead to manic episodes in people who are bipolar or suffer from major depression, contribute to dementia in people with Alzheimer’s disease, and bring on psychosis in some people with schizophrenia.
If you are taking St. John’s wort, be mindful if you notice an allergic reaction, feelings of fatigue or restlessness, increased blood pressure, increased sensitivity to the sun, and an upset stomach.
It’s important to tell your doctor if you’re taking St. John’s wort because it does interact with several medications, including birth control pills, allergy medications, sedatives, medications for migraines and heart disease medications. Consult your doctor before taking St. John’s wort if you:
- have a bleeding disorder
- are suicidal or severely depressed
- have a weak immune system
- take drugs for HIV/AIDS
- have high cholesterol
- have seizures
- have a weak nervous system
- are prone to swelling
- have stomach or intestinal problems
- have cataracts
- have diabetes
- The flowers of the St. John’s wort plant have been used medicinally for thousands of years. Today, St. John’s wort teas, extracts, capsules and powders are available in your local health food store.
- Today, St. John’s wort is used to improve symptoms of depression, anxiety, OCD, menopause and PMS. It also helps to soothe skin irritations, may help to fight cancer and supports smoking cessation.
- The standard dose for St. John’s wort is 300 milligrams, three times daily. Keep in mind, it takes several weeks to feel the benefits of this herb, so you’ll need to be patient.
- Do not take more than the standard dose without consulting with your healthcare professional first. And if you are taking any medications, seek advice from your doctor before using St. John’s wort.